JP6731624B2 - Organic semiconductor device manufacturing method and powder - Google Patents

Description

The present invention relates to a method for manufacturing an organic semiconductor device and a powder used for the method.

A method of forming a thin film of an organic semiconductor material between electrodes to obtain an organic semiconductor device has been prosperous in recent years because it can be manufactured by a low temperature process, has excellent flexibility, and can be made into a lightweight and durable organic semiconductor device. Came to be researched by.

However, conventionally, many of the organic semiconductor materials that have been used for organic semiconductor devices are hardly soluble in organic solvents, and therefore it is not possible to form the thin film using an inexpensive method such as coating or printing, It was common to form the thin film on the substrate by a relatively expensive vacuum deposition method or the like. Recently, there has been active research on forming an organic semiconductor thin film by a method using inkjet or flexographic printing, coating such as coating, or a method using printing, and a relatively high carrier mobility (hereinafter, When appropriate, organic semiconductor devices having “mobility”) have been obtained. It is expected that the above-mentioned method using coating or printing has a high throughput in the process of producing a field effect transistor and that a large-area field effect transistor can be manufactured at low cost.

Generally, the organic semiconductor thin film is formed by a vacuum process such as a vacuum deposition method or a coating process such as a spin coating method or a blade coating method using a solvent. However, the method of forming an organic semiconductor thin film by the vacuum process has a drawback that equipment for performing the vacuum process is required and that the loss of the organic semiconductor material increases. Also in the method of forming the organic semiconductor thin film by the coating process, since the organic semiconductor solution is coated on the entire substrate, the loss of the organic semiconductor material increases as in the vacuum process.

As another method for forming an organic semiconductor thin film, a printing method such as an inkjet method is known. In the printing method, various examinations have been made with the expectation that it is possible to apply a required amount of organic semiconductor material to a target position, and instead of the vacuum process, a large area and high-speed printing are possible. In the current printing method, a volatile organic solvent such as a halogen solvent or an aromatic solvent is required to dissolve the organic semiconductor material. These organic solvents are not necessarily the most suitable printing method from the viewpoint of not only the direct influence on the worker but also the global environment protection. Therefore, a solventless patterning technique is required as a sustainable technique that has a low environmental load.

A printing technique typified by OPC (organic photoconductor) is well known as a technique using an organic semiconductor material in such a printing method without using a solvent. However, the charge transport layer itself used in OPC does not use a solvent. It is formed by the method used, the surface of the photoreceptor is charged by corona discharge, etc., and the charge generated by laser irradiation is transported to the surface layer or lower layer to form a latent image.It does not pattern the organic semiconductor material itself. Absent. Several techniques for forming an organic semiconductor material by using electrostatic force (charging) have been studied from such a technique of the photoconductor. In Patent Documents 1 to 3, it is possible to pattern an organic semiconductor material by charging an electrode of a device constituent element and supplying a solution of the organic semiconductor material charged to a charge opposite to that of the electrode by an inkjet method or a spray coating method. It has been known. However, any method is a printing method using an organic solvent, and a method of forming an organic semiconductor layer without a solvent has not been suggested.

In addition, in the printing method using an organic solvent, in addition to the need to dry the solvent, in order to control the orientation direction of the crystals generated from the solution, a precise process such as temperature, atmosphere, treatment of the coated surface, etc. It is necessary to slowly form an organic semiconductor thin film while controlling, or to perform firing for several minutes to several tens of minutes for crystal growth after crystal formation. Therefore, the current printing method has a problem that it is necessary to use a solvent that has a negative influence on the environment, and a method for forming an organic semiconductor thin film with high throughput cannot be realized. In addition, at present, the method of manufacturing an organic semiconductor device by a conventional method of forming an organic semiconductor thin film, such as coating or printing, is not sufficient for practical use in terms of organic semiconductor device performance such as mobility.

As a method for controlling the crystal with high throughput, a thermal laminating method such as Patent Document 4 is known, but it is limited to a method for controlling the crystal of a semiconductor material formed by using a molten state or a coating/printing method without using a solvent. There is no specific example of patterning the organic semiconductor material with.

JP, 2005-12061, A JP, 2011-3442, A JP, 2008-78339, A International Publication No. 2014/136942

Physica Status Solidi RRL, 7, 1093 (2013)

An object of the present invention is to provide a method for producing an organic semiconductor device capable of forming an organic semiconductor thin film without using a solvent and in a short time, and a powder that can be used in the method.

The present inventors have conducted extensive studies to solve the above-mentioned problems, and as a result, without using a solvent, positively or negatively charged powder containing an organic semiconductor material was patterned on a substrate by applying an electrostatic field (desired site It was found that a method for producing an organic semiconductor device including a step of spraying) can produce an organic semiconductor device without a solvent and at a high throughput, and has completed the present invention.

That is, the method for producing an organic semiconductor device of the present invention is a method for producing an organic semiconductor device by patterning an organic semiconductor material, in which charged powder containing the organic semiconductor material is applied onto a substrate by applying an electrostatic field. It is characterized by including a step of patterning.

The powder of the present invention is a charged powder and is characterized by containing an organic semiconductor material.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a method for producing an organic semiconductor thin film which is solvent-free and can be processed in a short time, has a low environmental load, and has a high throughput, and a powder which can be used in the method.

It is a schematic diagram showing the composition of the powder patterning device used for spraying the organic semiconductor material concerning one embodiment of the present invention. It is a schematic diagram showing the composition of the thermal laminator used for thinning the organic semiconductor material concerning one embodiment of the present invention. The organic semiconductor material according to an embodiment of the present invention is a schematic diagram showing an ultrasound soluble adhesive machines used for thinning. 3 is a polarization micrograph of a powder containing a charged organic semiconductor material obtained by mixing an organic semiconductor material and carrier particles in an example of the present invention. 3 is a polarization microscope photograph of a substrate before an organic semiconductor material is dispersed on the substrate by a DC voltage in one example of the present invention. 4 is a polarization micrograph of a substrate after the organic semiconductor material is sprayed on the substrate by a DC voltage in one example of the present invention. 3 is a polarization microscope photograph of a substrate before an organic semiconductor material is dispersed on the substrate by an AC voltage in one example of the present invention. 3 is a polarization microscope photograph of a substrate after the organic semiconductor material is sprayed on the substrate by an AC voltage in one example of the present invention. 3 is a polarization micrograph of an organic semiconductor material sprayed before being made into a thin film by a thermal lamination method according to an example of the present invention. 3 is a polarization micrograph of an organic semiconductor thin film obtained by thinning a dispersed organic semiconductor material according to an example of the present invention by a thermal lamination method. It is the schematic which shows the structural aspect example of the organic thin-film transistor as an example of the organic semiconductor device of this invention.

The present invention will be described in detail.
A first object of the present invention is to provide a method for producing an organic semiconductor device without solvent and with high throughput.

The method for manufacturing an organic semiconductor device of the present invention includes a step of spraying a charged powder containing an organic semiconductor material onto a base material by applying an electrostatic field to perform patterning, and patterning the organic semiconductor material without using a solvent. It is characterized by being able to. The method for producing an organic semiconductor device of the present invention further includes a step of thinning the organic semiconductor material on the substrate by heat and pressure, if necessary, and in this case, the steps from patterning to thinning should be performed consistently without solvent. You can

The production method of the present invention includes a powder containing a charged organic semiconductor material, a powder containing a charged organic semiconductor material and charged carrier particles (described later), and an uncharged organic semiconductor material and a charged carrier. Any powder including powder and particles can be used.

The essential step of the method for manufacturing an organic semiconductor device of the present invention is a step of spraying a charged powder containing an organic semiconductor material onto the surface of a base material by applying an electrostatic field to perform patterning (hereinafter referred to as “patterning step”). Is. The patterning step is, for example, a step of transferring charged powder of an organic semiconductor material made of a semiconducting organic compound onto a substrate surface by applying a voltage. According to the above method, the organic semiconductor material can be dispersed in a desired pattern on a desired portion of the surface of the base material without using a solvent.

An embodiment of a powder patterning apparatus suitably used for a patterning step in the method for manufacturing an organic semiconductor device of the present invention will be described below based on FIG. It should be noted that members having the same function in each drawing are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 1, a powder patterning device 20 for patterning charged powder containing an organic semiconductor material on a substrate 21 includes a holder 22 for holding the charged powder containing an organic semiconductor material. , An electrode 23 for applying an electrostatic field to the powder, a wiring 24 for supplying a voltage to the holder 22 or the electrode 23, and a vertical direction (Z-axis direction) on which the base material 21 is placed. And a movable stage 25.

In order to spray the charged powder containing the organic semiconductor material, the holder 22 holding the charged powder containing the organic semiconductor material is moved onto the base material 21, and the powder is applied to the holder 22 or the electrode 23 on the base material 21 side. By applying a voltage having a polarity opposite to the charging polarity of the body, the charged organic semiconductor material is separated from the holder 22 by electrostatic force, and is dispersed on the base material 21 fixed to the stage 25. The voltage applied to the holder 22 or the electrode 23 on the base material 21 side may be either a DC voltage or an AC voltage.

The position where the organic semiconductor material is sprayed is a position where a voltage is applied to the electrode 23 on the holder 22 or the base material 21 side, and the organic semiconductor material is patterned at a desired position on the base material 21 by controlling the program of the applied voltage. be able to. The patterning accuracy may change depending on the distance between the base material 21 and the holder 22. The distance between the base material 21 and the holder 22 depends on the fineness of the pattern to be created, but is usually 10 mm or less, and preferably 1 mm or less. Further, the spray amount can be controlled by the magnitude of the voltage applied to the electrode 22 on the holder 22 or the substrate 21 side, the number of times the voltage is applied, and the like. These voltages are supplied from an external power source connected to the holder 22 or the electrode 23.

The holder 22 that holds the charged powder is preferably a magnet. When magnetic carrier particles are used to charge the powder and a magnet is used as the holder 22, the carrier particles are not scattered on the base material 21 but are held by the magnet serving as the holder 22, and thus the organic material having no magnetism is used. Only the semiconductor material can be dispersed on the base material 21 by electrostatic force.

The organic semiconductor material provided on the substrate by the patterning step functions as an organic semiconductor as it is, but in order to improve semiconductor characteristics, a step of thinning the organic semiconductor material scattered on the base material (hereinafter, referred to as “thin film”). It is preferable to carry out after the patterning. By passing through the thinning step, the fine-particle organic semiconductor material can be formed into a uniform thin film.

The thinning step is characterized by applying heat and pressure to the organic semiconductor material to thin the organic semiconductor material to form an organic semiconductor thin film made of the organic semiconductor material. According to the above method, the characteristics of the organic semiconductor thin film can be improved by a short-time treatment. Further, in the above method, even when pressure is applied to the organic semiconductor material in the cooling process after the end of ultrasonic vibration application, cracks may occur in the organic semiconductor thin film due to phase changes in the cooling process. Hard to happen.

As a method of forming a thin film while applying heat and pressure to an organic semiconductor material, a hot pressing method described in Non-Patent Document 1, a method of laminating with a heat roll as disclosed in Patent Document 4, and an organic semiconductor material can be used. Examples of the method include applying ultrasonic vibration while applying pressure. Considering throughput, a method of laminating with a heat roll and a method of applying ultrasonic vibration to the organic semiconductor material while applying pressure are preferable.

In a method of laminating using a heat roll, which is an example of a method of forming a thin film while applying heat and pressure to an organic semiconductor material, a general heat laminator composed of a heat roll can be used. An example of such a general thermal laminator is shown in FIG. As shown in FIG. 2, the thermal laminator 30 of this example includes a pair of thermal rolls 31 and a pair of thermal rolls 32 for applying heat and pressure to an object to be treated 34 containing an organic semiconductor material, and an object to be treated. And a feed roll 33 for feeding 34 to the outside of the thermal laminator 30.

When the general thermal laminator 30 shown in FIG. 2 is used, an object to be processed containing an organic semiconductor material (organic semiconductor material alone, combination of organic semiconductor material and base material, organic semiconductor material and protective film or protective layer) Or a combination of an organic semiconductor material, a base material, and a protective film or a protective layer) 34 is sandwiched between a pair of heat rolls 31 and a pair of heat rolls 32 to heat the contact portions of the heat rolls 31 and 32 and The organic semiconductor material can be thinned by utilizing the nip pressure between the pair of heat rolls 31 and 32. After being thinned, the object to be processed 34 is sent to the outside of the thermal laminator 30 via the feed roll 33.

In the method of performing ultrasonic treatment while applying pressure, which is an example of the method for manufacturing an organic semiconductor device of the present invention, a method using a general ultrasonic welding machine (ultrasonic welder) used for pressure bonding of a packaging film and the like can be mentioned. To be When using a general ultrasonic welding machine, ultrasonic vibration is applied from above the object to be processed containing the organic semiconductor material while applying pressure to the organic semiconductor material with the ultrasonic welding machine. The organic semiconductor material can be thinned by utilizing the friction heat and pressure. A general ultrasonic welding machine includes a horn as a pressing member that is pressed against an object to be processed to apply pressure to the object and to apply ultrasonic vibration.

An example of such a general ultrasonic welding machine is shown in FIG. As shown in FIG. 3, the ultrasonic welding machine 40 of the present embodiment includes an ultrasonic oscillator (generator) 41 for oscillating ultrasonic waves, an ultrasonic transducer (converter) 42 for generating ultrasonic vibrations, and an ultrasonic wave. A booster 43 for amplifying vibration, a horn 44, a pressurizing mechanism (press unit) 45 for applying pressure to the object to be processed, and a heating stage 46 on which the object to be processed are arranged are provided. .. The pressurizing mechanism 45 includes an arm portion 45a to which the ultrasonic transducer 42, the booster 43, and the horn 44 are attached, and a support pillar 45b that slidably supports the arm portion 45a in the vertical direction. The heating stage 46 includes a heater 46a for heating the upper surface of the heating stage 46 to a predetermined temperature.

In these thinning steps, the organic semiconductor material may be used alone as an object to be treated, but an organic semiconductor material arranged on a substrate is used as an object to be treated, and It is more preferable to perform the above treatment on the semiconductor material. In the method of the present invention, by subjecting the organic semiconductor material on the substrate to the above treatment, the powder of the organic semiconductor material of the order of micron or submicron becomes an organic semiconductor thin film of several tens to several hundreds of nanometers at the same time Reorientation of the crystal occurs and the crystal orientation can be made uniform.

Further, when the organic semiconductor material is sprayed in the patterning step, the position where the organic semiconductor material is sprayed is a desired position where the organic semiconductor thin film is to be formed (for example, in the case of manufacturing an organic thin film transistor, the source on the substrate is Even if it is slightly displaced from the position (between the electrode and the drain electrode), the organic semiconductor material is spread in the surface direction of the substrate by the thinning step, so that the organic semiconductor thin film can be formed at a desired position.

In the step of thinning the organic semiconductor material, a material in which the organic semiconductor material is sandwiched between a pair of base materials is used as an object to be processed. It is more preferable to perform the treatment. That is, in the thinning process of the organic semiconductor material, for example, between one and placing the other one substrate onto the organic semiconductor material which is patterned on a substrate an organic semiconductor material a pair of substrates It is more preferable that the organic semiconductor material is made into a thin film by sandwiching it between the substrates and applying heat and pressure simultaneously from the upper portion of the placed substrate. This makes it possible to prevent the organic semiconductor material from adhering to the contact portion (heat roll or ultrasonic vibration device) or stage used for thinning during the above treatment, and to reduce the organic semiconductor thin film due to phase change during the cooling process. It is possible to avoid cracks in the. As the base material, an inorganic substrate such as glass and various resin films, which are given as examples of the base materials 1 and 1′ constituting the organic thin film transistors 10A and 10B in the latter stage, and various resin films, and an electrode and/or an insulating layer are formed thereon. Examples thereof include a resin film, but a resin film is preferable.

The method of applying pressure to the organic semiconductor material is not particularly limited, but a method of using a nip pressure of a thermo roll (for example, 31 and 32 in FIG. 2) directly to the organic semiconductor material or through a protective film or protective layer, or A method of pressing a pressure member (for example, 44 in FIG. 3) is suitable. When pressure is applied to the organic semiconductor material through the protective film or protective layer, the organic semiconductor material sandwiched between the base material and the protective film or protective layer is used as the object to be treated, and It is more preferable to press the pressure member against the semiconductor material via the protective film or the protective layer. Thereby, the organic semiconductor thin film having a uniform thickness can be formed. The protective film or protective layer used here may be the same as or different from the base material. Further, in order to separate the organic semiconductor thin film from the protective layer after the organic semiconductor thin film is formed, a film having a protective layer laminated on the mold releasing material may be provided on the organic semiconductor material so that the mold releasing material contacts the organic semiconductor material. The protective film or protective layer will be described later.

The temperature of the organic semiconductor material when the organic semiconductor material is thinned by applying heat and pressure (hereinafter, appropriately referred to as “thinning processing”) is set according to the type of the organic semiconductor material. When the organic semiconductor material has a phase transition point (phase transition temperature), it is preferable to adjust the temperature of the organic semiconductor material during thinning treatment within a range of 0 to +80° C. with respect to the phase transition point of the organic semiconductor material. .. When the organic semiconductor material is used in combination with the base material, it is preferable to set the temperature of the organic semiconductor material during the thinning treatment to a temperature lower than the glass transition point (glass transition temperature) of the base material used. The optimum temperature range of the temperature of the organic semiconductor material during the thinning process is set by the combination of the phase transition point of the organic semiconductor material and the glass transition point of the base material.

In order to reduce the thickness of the organic semiconductor material, the temperature of the organic semiconductor material is preferably higher than the phase transition point (that is, liquid crystal transition point, glass transition point, melting point, etc.) of the organic semiconductor material. In this case, under such conditions, the organic semiconductor material becomes liquid when it undergoes a phase transition (phase change) from the solid phase to the liquid crystal phase, glass phase, liquid phase, etc. during the thinning process, and the applied pressure Is thinned by. In this case, the organic semiconductor material is recrystallized in the cooling process after the application of ultrasonic vibration is finished, and an organic semiconductor thin film is obtained. That is, in the step of forming the organic semiconductor thin film of the present invention, it is preferable that the organic semiconductor material is thinned by recrystallizing the organic semiconductor material after the solid phase organic semiconductor material is phase-transformed. As a result, the solid phase organic semiconductor material undergoes a phase transition to increase the fluidity of the organic semiconductor material, which facilitates the thinning of the organic semiconductor material. When the application of heat and pressure to the organic semiconductor material is finished, the temperature of the organic semiconductor material is rapidly lowered, and reorientation and recrystallization of the organic semiconductor material occur. The organic semiconductor thin film thus obtained is less prone to cracks between crystal grains than an organic semiconductor thin film obtained by a general solution process. Even when the organic semiconductor material does not undergo a phase transition during the thinning treatment, the organic semiconductor material may be thinned by receiving sufficient pressure while being heated by ultrasonic vibration.

One feature of the thinning step is that the crystals of the organic semiconductor material are considered to be reoriented and the orientation of the crystals is made uniform. Therefore, among these organic semiconductor materials, particularly when an organic semiconductor material having crystallinity is used, an organic semiconductor device having excellent semiconductor characteristics such as mobility can be easily obtained in a short time.

Through the step of spraying the above-mentioned organic semiconductor material and the step of forming an organic thin film by applying heat and pressure, an organic thin film used for an organic semiconductor device can be formed without using a solvent.

As a preferred embodiment of the patterning step, there is a method in which only carrier particles are magnetically separated from a charged powder containing an organic semiconductor material and carrier particles, and only the charged organic semiconductor material is dispersed on a base material.

The carrier particles referred to here are particles made of a magnetic material, and the carrier particles are made of a known magnetic material such as metals such as iron, ferrite and magnetite, and alloys of these metals with metals such as aluminum and lead. Magnetic particles are mentioned, and ferrite particles are preferable. Further, magnetic particles made of the above magnetic material, whose surface is coated with a resin or the like, magnetic fine powder dispersed in a resin, or the like can also be used as carrier particles. Examples of the simplest carrier particles include standard carriers commercially available from The Imaging Society of Japan. The average particle diameter of the carrier particles is usually 50 to 200 μm. After mixing the organic semiconductor material and carrier particles in a mass ratio of, for example, 3 to 15:97 to 85, the organic semiconductor material can be triboelectrically charged by stirring, shaking, or the like.

Alternatively, the organic semiconductor material may be pulverized in advance with a pulverizer such as a jet mill, a bead mill, a ball mill to a particle size of 1 to 20 μm, and then the obtained powder of the organic semiconductor material may be mixed with carrier particles. .. By mixing the powder of the organic semiconductor material with the carrier particles and then stirring and shaking the powder, the organic semiconductor material is charged positively or negatively, and the powder of the organic semiconductor material adheres to the carrier particles by electrostatic force.

The organic semiconductor device manufactured by the manufacturing method of the present invention is not particularly limited as long as it has a structure in which a semiconductor layer including an organic semiconductor thin film is sandwiched by a pair of electrodes, but is preferably an organic thin film transistor. In the organic semiconductor device manufactured by the manufacturing method of the present invention, two electrodes of a source electrode and a drain electrode are in contact with a semiconductor layer including an organic semiconductor thin film, and a current flowing between the source electrode and the drain electrode is applied to a gate. It is more preferable that the organic thin film transistor is configured to be controlled by a voltage applied to another electrode called a gate electrode via the insulating layer. That is, as the organic semiconductor device manufactured by the manufacturing method of the present invention, the organic semiconductor device arranged between the source electrode and the drain electrode and the source electrode and the drain electrode arranged so as to be separated from each other. A semiconductor layer including an organic semiconductor thin film made of a material, a gate electrode arranged to face the semiconductor layer, and an insulating layer (gate insulating layer) arranged between the semiconductor layer and the gate electrode. More preferred is an organic thin film transistor which is an organic field effect transistor comprising: It is further preferable that the organic field effect transistor includes the source electrode, the drain electrode, the semiconductor layer, the gate electrode, and the insulating layer on a base material.

A mode example of an organic thin film transistor manufactured by the manufacturing method of the present invention is shown in FIGS.
The organic thin film transistor 10A shown in FIG. 11(a) is called a bottom gate type organic field effect transistor. The organic thin film transistor 10A includes a base material 1, a gate electrode 2 laminated on the base material 1, a gate insulating layer 3 laminated on an upper surface of the gate electrode 2 (a back surface of a surface facing the base material 1), A source electrode 5 and a drain electrode 6 are provided on a part of the upper surface of the gate insulating layer 3 so as to be separated from each other, and an upper surface of the gate insulating layer 3 (however, the source electrode 5 and the drain electrode 6 are provided. A semiconductor layer 4 including an organic semiconductor thin film made of an organic semiconductor material, which is disposed on the upper surface of the semiconductor layer 4 (excluding a portion where the organic semiconductor material is provided).

The organic thin film transistor 10B shown in FIG. 11B is an organic field effect transistor, and includes a base material 1′, a gate insulating layer 3′ stacked on the base material 1′, and an upper surface (base) of the gate insulating layer 3′. The source electrode 5 and the drain electrode 6 which are arranged so as to be spaced apart from each other on a part of the back surface of the surface facing the material 1 ′, and the upper surface of the gate insulating layer 3 ′ (however, the source electrode 5 and the drain electrode 6 ). A semiconductor layer 4 including an organic semiconductor thin film made of an organic semiconductor material, a gate insulating layer 3 provided on an upper surface of the semiconductor layer 4, and a gate. The gate electrode 2 is stacked on the upper surface of the insulating layer 3, and the base material 1 is stacked on the upper surface of the gate electrode 2. In the organic thin film transistor 10B, one of the base material 1'and the gate insulating layer 3'may be omitted. Further, the organic thin film transistor of the present invention may be an organic thin film transistor having a structure (called a top gate type organic field effect transistor) in which both the base material 1'and the gate insulating layer 3'are removed from the organic thin film transistor 10B.

Next, each component in the embodiment of the organic thin film transistor manufactured by the manufacturing method of the present invention shown in FIGS. 11A and 11B will be described.

As the base materials 1 and 1', a resin film can be used in addition to an inorganic substrate such as glass. Considering the flexibility of the organic thin film transistors 10A and 10B, the substrates 1 and 1'are preferably resin films. Examples of the resin forming the resin film include polyethylene terephthalate, polyethylene naphthalate, polyether sulfone, polyamide, polyimide, polycarbonate, cellulose triacetate, and polyetherimide. The types of the substrates 1 and 1'are selected according to the process temperature at the time of applying pressure and applying ultrasonic vibration. Further, a flattening layer may be provided on the base materials 1 and 1 ′ in order to improve the smoothness of the surfaces of the base materials 1 and 1 ′. Inorganic oxide particles (for example, silica particles) having an average particle size on the order of nanometers (for example, 5 nm) may be dispersed in the resin forming the resin film in order to improve metal adhesion and durability. .. As these substrates 1 and 1 ′, those having a glass transition point of 100° C. or higher are preferable, and those having a glass transition point of 150° C. or higher are more preferable. The thickness of the substrates 1 and 1'is usually 1 μm to 10 mm, preferably 5 μm to 3 mm.

When a resin film is used as the base material 1, the semiconductor layer 4 may be sandwiched between the base materials 1 and 1'as in the organic thin film transistor 10B in consideration of bending resistance of the organic thin film transistor. In the case of this configuration, it is preferable that the materials of the two types of base materials 1 and 1'be the same. By using the substrates 1 and 1′ made of such a resin film, the organic thin film transistor can be made flexible, and a flexible and lightweight organic thin film transistor having high bending resistance can be realized. Is improved.

A conductive material (material having conductivity) is used for the source electrode 5, the drain electrode 6, and the gate electrode 2. Examples of the conductive material include platinum, gold, silver, aluminum, chromium, tungsten, tantalum, nickel, cobalt, copper, iron, lead, tin, titanium, indium, palladium, molybdenum, magnesium, calcium, barium, lithium. , Metals such as potassium, sodium, and alloys containing them; conductive inorganic oxides such as InO ₂ , ZnO ₂ , SnO ₂ , ITO (indium tin oxide); polyaniline, polypyrrole, polythiophene (PEDOT/PSS, etc.), polyacetylene, Conductive polymer compounds such as polyparaphenylene vinylene and polydiacetylene; carbon materials such as carbon nanotubes and graphite can be used. In order to reduce the contact resistance of the source electrode 5, the drain electrode 6, and the gate electrode 2, the above-mentioned various materials may be doped with molybdenum oxide, or the above metal may be treated with thiol or the like. .. Further, as the above-mentioned conductive material, a conductive composite material in which carbon black is dispersed in each of the above-mentioned materials and particles of a metal such as gold, platinum, silver, or copper are listed as various materials ( However, a conductive composite material dispersed in a material different from the particles) can also be used. Wirings are connected to the gate electrode 2, the source electrode 5, and the drain electrode 6 when operating the organic thin film transistors 10A and 10B. The wiring is also made of substantially the same material as the material of the gate electrode 2, the source electrode 5, and the drain electrode 6. The thickness of the source electrode 5, the drain electrode 6, and the gate electrode 2 varies depending on the material thereof, but is usually 1 nm to 10 μm, preferably 10 nm to 5 μm, and more preferably 30 nm to 1 μm.

The gate insulating layers 3 and 3′ are layers of an insulating material (material having an insulating property). Examples of the insulating material include polyparaxylylene, polyacrylate (acrylic resin) such as polymethylmethacrylate, polystyrene, polyvinylphenol, polyamide, polyimide, polycarbonate, polyester, polyvinyl alcohol, polyvinyl acetate, polyurethane, polysulfone, Polymers such as fluorine-based resins, epoxy resins and phenol resins, and copolymers combining them; inorganic oxides such as silicon dioxide, aluminum oxide, titanium oxide and tantalum oxide; ferroelectric inorganic oxides such as SrTiO ₃ and BaTiO _3. Materials; inorganic nitrides such as silicon nitride and aluminum nitride; inorganic sulfides; materials such as inorganic fluorides in which dielectric particles are dispersed in a polymer can be used. It is preferable that the insulating material used for the gate insulating layer 3 be checked in advance for damage due to pressurization and application of ultrasonic vibration, and similar to the base material 1, thermal stability is required. It is also necessary to consider dielectric breakdown after the treatment of applying ultrasonic vibration. The thickness of each of the gate insulating layers 3 and 3′ varies depending on the insulating material used, but is usually 10 nm to 10 μm, preferably 50 nm to 5 μm, and more preferably 100 nm to 1 μm. In the case of the organic thin film transistor 10B having a structure in which the semiconductor layer 4 is sandwiched between the two base materials 1 and 1′ as shown in FIG. 11B, the gate insulating layers 3 and 3′ have the bending resistance of the organic thin film transistor 10B taken into consideration. Then, it is preferable to use the same material.

The semiconductor layer 4 includes the organic semiconductor thin film made of the organic semiconductor material described above. As the semiconductor material forming the semiconductor layer 4, the organic semiconductor material described above may be used alone, or the organic semiconductor material described above may be used in combination with another semiconductor material. In order to improve the characteristics of the organic thin film transistors 10A and 10B, various additives may be mixed with the semiconductor material forming the semiconductor layer 4 if necessary. The thickness of the semiconductor layer 4 is preferably as thin as possible so long as the necessary functions are not lost. In the organic thin film transistors 10A and 10B, the characteristics of the organic thin film transistors 10A and 10B do not depend on the thickness of the semiconductor layer 4 as long as the semiconductor layer 4 has a thickness equal to or larger than a predetermined value. Often increases. Conversely, if the thickness of the semiconductor layer 4 is too thin, it is not possible to form a channel for the charge in the semiconductor layer 4, so the semiconductor layer 4 needs to have an appropriate thickness. The thickness of the semiconductor layer 4 for exhibiting the required functions of the organic thin film transistors 10A and 10B is usually 1 nm to 5 μm, preferably 10 nm to 1 μm, and more preferably 10 nm to 500 nm.

In the organic thin-film transistor manufactured by the manufacturing method of the present invention, another layer may be provided between the above-mentioned constituent elements or on the exposed surface of each constituent element as required. For example, a thin film transistor protection layer for protecting the organic thin film transistor 10A may be formed directly or through another layer on the semiconductor layer 4 in the organic thin film transistor 10A. Thereby, the influence of outside air such as humidity on the electrical characteristics of the organic thin film transistor can be reduced, and the electrical characteristics of the organic thin film transistor can be stabilized. In addition, the electrical characteristics such as the on/off ratio of the organic thin film transistor can be improved.

The material forming the thin film transistor protective layer is not particularly limited, but examples thereof include epoxy resins, acrylic resins such as polymethylmethacrylate, polyurethanes, polyimides, polyvinyl alcohol, fluororesins, various resins such as polyolefins; silicon oxide, aluminum oxide. Inorganic oxides such as; and dielectrics such as nitrides such as silicon nitride are preferable, and resins (polymers) having small oxygen permeability, moisture permeability, and water absorption are more preferable. As a material for forming the thin film transistor protective layer, a gas barrier protective material developed for organic EL displays can also be used. The thin film transistor protective layer may have any thickness depending on its purpose, but is usually 100 nm to 1 mm.

In the method for manufacturing an organic semiconductor device of the present invention, for example, an organic semiconductor material is dispersed on a base material on which an insulating layer and an electrode are formed by controlling the above voltage application, and heat and heat are applied to the organic semiconductor material. An organic semiconductor device is manufactured by forming a thin film while applying pressure.

In the method for manufacturing an organic semiconductor device of the present invention, the organic semiconductor device includes a source electrode and a drain electrode arranged so as to be separated from each other, and an organic semiconductor arranged between the source electrode and the drain electrode. A semiconductor layer including an organic semiconductor thin film made of a material, a gate electrode arranged to face the semiconductor layer, and an insulating layer arranged between the semiconductor layer and the gate electrode on a substrate. In the case of an organic thin film transistor which is an organic field effect transistor provided in, it is preferable to perform a step of patterning charged powder containing an organic semiconductor material on the base material before forming the organic semiconductor thin film. With this manufacturing method, the organic thin film transistor 10A shown in FIG. 11A and the organic thin film transistor 10B shown in FIG. 11B can be manufactured.

Here, the manufacturing method of the organic semiconductor device of the present invention will be described in detail based on the organic thin film transistor 10B of the embodiment example of FIG. 11B using two types of substrates. (Referred to as "gate board") The first substrate is formed by laminating a gate electrode 2 and the gate insulating layer 3 on the substrate 1. (Referred to as source-drain board) the other substrate, a and the source electrode 5 'gate insulating layer 3 on the' substrate 1 is obtained by laminating a drain electrode 6. Further, in the following description, the case where the semiconductor layer 4 is composed of only the organic semiconductor thin film will be described.

(Creation of the gate based on plate)
[Treatment of Substrates 1 and 1']
Gate board is made by providing the gate electrode 2 and the gate insulating layer 3 on the substrate 1 described in the above. The surface of the base material 1 may be subjected to a surface treatment (cleaning treatment) in order to improve the wettability of each layer laminated on the base material 1 (ease of lamination). Examples of the surface treatment include acid treatment with hydrochloric acid, sulfuric acid, acetic acid, etc.; alkali treatment with sodium hydroxide, potassium hydroxide, calcium hydroxide, ammonia, etc.; ozone treatment; fluorination treatment; plasma with plasma such as oxygen or argon. Treatment: Langmuir-Blodgett film formation treatment; electrical treatment such as corona discharge.

[Formation of gate electrode 2]
The gate electrode 2 is formed on the base material 1 using the above conductive material (electrode material). Examples of the method for forming the gate electrode 2 include a vacuum vapor deposition method, a sputtering method, a coating method, a thermal transfer method, a printing method, a sol-gel method and the like. It is preferable to perform patterning as needed so that the conductive material has a desired shape during or after the film formation of the conductive material. Various methods can be used as the patterning method, and examples thereof include a photolithography method in which photoresist patterning and etching are combined. Further, as a patterning method, it is also possible to use a printing method such as inkjet printing, screen printing, offset printing, letterpress printing, a soft lithography method such as a microcontact printing method, and a method combining a plurality of these methods. The electrode formed by the printing method is baked by applying energy such as heat and light until the desired conductivity is reached.

[Formation of gate insulating layer 3]
Next, the gate insulating layer 3 is formed on the gate electrode 2 formed on the base material 1 using the above insulating material (see FIG. 11B). Examples of the method for forming the gate insulating layer 3 include coating methods such as a spin coating method, a spray coating method, a dip coating method, a casting method, a bar coating method, and a blade coating method; a screen printing method, an offset printing method, an inkjet method, and the like. Printing method; a vacuum deposition method, a molecular beam epitaxial growth method, an ion cluster beam method, an ion plating method, a sputtering method, an atmospheric pressure plasma method, a dry process method such as a CVD (chemical vapor deposition) method, and the like. The gate insulating layer 3 may be surface-treated. By subjecting the gate insulating layer 3 to the surface treatment, it becomes easier to control the molecular orientation and crystallinity at the interface between the semiconductor layer 4 and the gate insulating layer 3 which are subsequently formed, and the substrate 1 and the gate insulating layer 3 are controlled. It is considered that the characteristics such as the carrier mobility of the organic thin film transistor 10B are improved by reducing the trapped portion on No. 3. The trap site refers to a functional group such as a hydroxyl group existing in the untreated base material 1 or the gate insulating layer 3, and when such a functional group exists in the base material 1 or the gate insulating layer 3, Electrons are attracted to the functional groups, and as a result, the carrier mobility of the organic thin film transistor 10B is reduced. Therefore, reducing the trap sites in the base material 1 and the gate insulating layer 3 may be effective in improving the characteristics such as carrier mobility of the organic thin film transistor 10B.

(Creation of the source and drain board)
[Treatment of substrate 1']
Gate board is 'the gate insulating layer 3 on the' substrate 1 described in the above, is produced by the source electrode 5, and a drain electrode 6 provided. Similar to the surface of the base material 1, the surface of the base material 1 ′ may be subjected to the above-mentioned surface treatment.

[Formation of gate insulating layer 3']
Next, the gate insulating layer 3′ is formed on the base material 1′ by using the above insulating material (see FIG. 11B). As a method for forming the gate insulating layer 3′, the same method as the method for forming the gate insulating layer 3 can be used. Similarly to the gate insulating layer 3, the gate insulating layer 3 ′ may be surface-treated.

[Formation of Source Electrode 5 and Drain Electrode 6]
Next, the source electrode 5 and the drain electrode 6 are formed on the gate insulating layer 3′ by using the above conductive material. The materials of the source electrode 5 and the drain electrode 6 may be the same or different. As a method of forming the source electrode 5 and the drain electrode 6, the same method as the method of forming the gate electrode 2 can be used. The conductive material forming the source electrode 5 and the drain electrode 6 may be doped with molybdenum oxide or the like in order to reduce the contact resistance of the source electrode 5 and the drain electrode 6. When the source electrode 5 and the drain electrode 6 are made of metal, the metal may be treated with thiol or the like. Molybdenum oxide, thiol, or the like can be stacked on the source electrode 5 and/or the drain electrode 6 by a method similar to the method of forming a conductive material.

[Spraying of the organic semiconductor material of the source and drain board on]
Then, to spray an organic semiconductor material in the source and drain board on using the powder patterning device 20. As described above, the method of spraying is to apply a voltage having the same polarity as the organic semiconductor to the holder 22 holding the powder containing the charged organic semiconductor or a voltage having the opposite polarity to the charge of the organic semiconductor to the electrode 23 on the substrate side from the external voltage. When applied, the organic semiconductor material is separated from the holder 22 by electrostatic force, and is dispersed on the base material 21 fixed to the stage 25.

The holder that holds the charged organic semiconductor material is preferably a magnet. When carrier particles having magnetism are used to charge the organic semiconductor material, the carrier particles are held by the magnet, which is the holder, and thus are not scattered on the base material. It can be spread on a substrate. Therefore, it is possible to separate carrier particles that can affect the function of the organic semiconductor device.

In the patterning step, powder can be patterned on the source electrode, the gate electrode, or a position in the vicinity thereof. Also, the organic semiconductor material can be sprayed on the region (channel) on or near the between the source electrode 5 and drain electrode 6 in the source and drain board on. The position where the organic semiconductor material is sprayed depends on the amount of the organic semiconductor material, but in order to obtain a good organic semiconductor thin film, it is preferable to pattern the organic semiconductor material in the vicinity of the channel such as on the electrode.

[Formation of Semiconductor Layer 4 and Organic Thin Film Transistor 10B]
Next, a gate board, superimposed on the source and drain board which organic semiconductor material disposed thereon. Using those interposing an organic semiconductor material between the thus obtained drain group Ita及 beauty gate board is subjected to thinning processing in through the gate board the organic semiconductor material This gives energy to the organic semiconductor material. Thus, at the same time when the semiconductor layer 4 made of an organic semiconductor thin film organic semiconductor material is thinned it is formed as a channel, and the source and drain board and the gate board are crimped, the organic thin film transistor 10B is completed. The organic thin film transistor 10B is manufactured under the same conditions as the above-described method for forming the organic semiconductor thin film as the conditions for the thinning process. The organic semiconductor thin film can be formed in an extremely short time by optimizing the conditions of pressurization and application of ultrasonic vibration without requiring a long baking process as in the past.

Generally, the operating characteristics of an organic thin film transistor include carrier mobility and conductivity of a semiconductor layer, capacitance of an insulating layer, device configuration (distance between source electrode and drain electrode, width of source electrode and drain electrode, insulating layer, insulating layer). Thickness etc.) etc. In order to obtain the semiconductor layer 4 made of an organic semiconductor material having a high carrier mobility, the organic semiconductor material has an orientational order in a certain direction (more uniform crystals are orientated in a certain direction. Is required. In the method for manufacturing an organic semiconductor device of the present invention, further including a thinning step, in the process of cooling the organic semiconductor material after the completion of the application of heat and pressure, the crystals of the organic semiconductor material are reoriented, and the crystal is kept constant. The semiconductor layer 4 made of an organic semiconductor material having an orientational order in the direction can be obtained. Further, in the organic thin film transistor 10B having the two base materials 1 and 1′ and the two gate insulating layers 3 and 3′, the same material is used for the base materials 1 and 1′ and the gate insulating layers 3 and 3′ are used. If the same material is used, the structure of the organic thin film transistor 10B can be a symmetrical sandwich structure around the semiconductor layer 4. As a result, it is possible to obtain the organic thin film transistor 10B that is not easily affected by distortion due to different materials and has high bending resistance.

Furthermore, in the method for producing an organic semiconductor device of the present invention, which further includes a thinning step, the organic semiconductor thin film can be formed in a short time. Also, compared to the conventional manufacturing method of forming an organic semiconductor thin film by another coating method or printing method (solution process), it has higher throughput and is also very low cost, and is also applied to the manufacture of organic semiconductor devices for large area display applications. it can. Further, in the method for producing an organic semiconductor device of the present invention, which further includes a thinning step, the organic semiconductor thin film can be formed in a short time, so that the sheet-to-sheet method or the roll-to-roll method is used. It is also possible to implement the method.

A second object of the present invention is to provide a material suitable for the method for manufacturing an organic semiconductor device of the present invention. The material of the present invention is a charged powder containing an organic semiconductor material. The organic semiconductor material preferably contains a charged organic semiconductor material. The powder of the present invention preferably further contains carrier particles for charging the organic semiconductor material.

As the organic semiconductor material, any of a low molecular weight organic semiconductor compound, a high molecular weight organic semiconductor compound, and an oligomer organic semiconductor compound can be used. As the low molecular weight organic semiconductor compound, polyacene, a part of carbon atoms of polyacene is substituted with a nitrogen atom, an atom such as a sulfur atom, an oxygen atom, or a polyvalent functional group such as a carbonyl group, or polyacene In which a part of the hydrogen atoms of is substituted with a monovalent functional group such as an aryl group, an acyl group, an alkyl group or an alkoxyl group (a triphenodioxazine derivative, a triphenodithiazine derivative, represented by the general formula (1) described later). Thienothiophene derivative). In addition, as the above-mentioned low molecular weight organic semiconductor compound, styrylbenzene derivatives, metal phthalocyanines, condensed ring tetracarboxylic acid diimides, dyes such as merocyanine dyes and hemicyanine dyes, and tetrakis(octadecylthio)tetrathiafulvalene are typical. The charge transfer complex etc. which are mentioned are mentioned. Examples of the condensed ring tetracarboxylic acid diimides include naphthalene-1,4,5,8-tetracarboxylic acid diimide and N,N'-bis(4-trifluoromethylbenzyl)naphthalene-1,4,5,8- Tetracarboxylic acid diimide, N,N'-bis(1H,1H-perfluorooctyl)naphthalene-1,4,5,8-tetracarboxylic acid diimide, N,N'-bis(1H,1H-perfluorobutyl)naphthalene- 1,4,5,8-Tetracarboxylic acid diimide, N,N'-dioctylnaphthalene-1,4,5,8-tetracarboxylic acid diimide, naphthalene-2,3,6,7-tetracarboxylic acid diimide, etc. Naphthalene tetracarboxylic acid diimides; anthracene-2,3,6,7-tetracarboxylic acid diimides and other anthracene tetracarboxylic acid diimides.

Examples of the polymer organic semiconductor compound include polypyrroles such as polypyrrole, poly(N-substituted pyrrole), poly(3-substituted pyrrole), poly(3,4-disubstituted pyrrole); polythiophene, poly(3- Polythiophenes such as substituted thiophene), poly(3,4-disubstituted thiophene), and polybenzothiophene; polyisothianaphthenes such as polyisothianaphthene; polythienylenevinylenes such as polythienylenevinylene; poly(p -Poly(p-phenylene vinylene)s such as phenylene vinylene; polyanilines such as polyaniline, poly(N-substituted aniline), poly(3-substituted aniline), poly(2,3-disubstituted aniline); polyacetylene, etc. Polyacetylenes; polydiacetylenes and other polydiacetylenes; polyazulenes and other polyazulenes; polypyrene and other polypyrenes; polycarbazoles and poly(N-substituted carbazoles) and other polycarbazoles; polyselenophene and other polyselenophenes; Polyfurans such as polyfuran and polybenzofuran; poly(p-phenylene)s such as poly(p-phenylene); polyindoles such as polyindole; polypyridazines such as polypyridazine; polysulfides such as polyphenylene sulfide and polyvinylene sulfide And the like.

Examples of the oligomer organic semiconductor compound include an oligomer having the same repeating unit as the above polymer, for example, α-sexithiophene which is a thiophene hexamer, α,ω-dihexyl-α-sexithiophene, α,ω-dihexyl-α. -Quinkethiophene, α,ω-bis(3-butoxypropyl)-α-sexithiophene, and other oligomers.

In carrying out the present invention, the organic semiconductor material is preferably a crystalline low molecular weight organic semiconductor compound. An example of a particularly preferable crystalline low molecular weight organic semiconductor compound is a thienothiophene derivative represented by the following general formula (1).

In formula (1), R ₁ and R ₂ each independently have a hydrogen atom, an alkyl group, an alkenyl group which may have a substituent, an alkynyl group which may have a substituent, or a substituent. Optionally represents an aryl group, a heterocyclic group optionally having a substituent, an alkoxyl group, or an alkoxyalkyl group, R ₁ and R ₂ may be the same or different, and m and n are respectively Represents 0 or 1 independently.

The alkyl group is a linear, branched or cyclic aliphatic hydrocarbon group, preferably a linear or branched aliphatic hydrocarbon group, and more preferably a linear aliphatic hydrocarbon group. is there. The alkyl group has usually 1 to 36 carbon atoms, preferably 2 to 24 carbon atoms, more preferably 4 to 20 carbon atoms, and further preferably 4 to 10 carbon atoms. The above-mentioned alkenyl group and alkynyl group are aliphatic hydrocarbon groups having a double bond or a triple bond in the molecular chain, and the carbon number thereof is usually 1 to 36, and the following aryl group and heterocycle as a substituent. It can also have a group.

The aryl group is a phenyl group, biphenyl group, pyrene group, xylyl group, mesityl group, cumenyl group, benzyl group, phenylethyl group, α-methylbenzyl group, triphenylmethyl group, styryl group, cinnamyl group, biphenylyl group, An aromatic hydrocarbon group such as a 1-naphthyl group, a 2-naphthyl group, an anthryl group, and a phenanthryl group. The heterocyclic group is a 2-thienyl group, a benzothienyl group, a thienothienyl group, or the like. Each of these aryl group and heterocyclic group may have a substituent such as the above-mentioned alkyl group, and when having a plurality of substituents, the plurality of substituents may be the same or different.

In order that the thienothiophene derivative represented by the general formula (1) has a phase transition point in the range of 70° C. to 280° C., it is preferable that at least one of R ₁ and R ₂ is an alkyl group. The length of the alkyl chain is preferably 4 or more carbon atoms.

In addition, polystyrene, styrene-methacrylic acid copolymer, styrene-acrylic acid copolymer, binder resin such as styrene-acrylic acid ester copolymer, silica, if necessary, within a range not impairing the function of the organic semiconductor device. An external additive composed of fine particles such as alumina and titanium oxide, wax, a charge control agent and the like may be added to the powder. By adding these, transferability, fluidity, developability, chargeability, etc. of the powder can be improved.

A charged powder containing such an organic semiconductor material can be applied to the method for manufacturing an organic semiconductor device of the present invention, and is sprayed to a desired position by applying a voltage to an electrode on a holder or a base material of a powder patterning device. It is possible to perform patterning without using a conventional vacuum process or a coating or printing process that requires a volatile organic solvent such as a halogen-based solvent or an aromatic solvent.

The organic semiconductor device manufactured in this manner can be used as a switching element or the like of an active matrix of a display. Examples of the display include a liquid crystal display, a polymer-dispersed liquid crystal display, an electrophoretic display, an electroluminescence (EL) display, an electrochromic display, and a particle rotation display. The organic semiconductor device of the present invention can also be used as a digital element or an analog element such as an element of a memory circuit, an element of a signal driver circuit, or an element of a signal processing circuit, and by combining these elements, an IC (integrated circuit) is provided. It is possible to make cards and IC tags. Furthermore, since the organic semiconductor device of the present invention can change its characteristics by external stimuli such as chemical substances, it can be expected to be used as an FET (field effect transistor) sensor.

Hereinafter, the present invention will be described in more detail with reference to examples, but these examples are merely for facilitating the understanding of the present invention, and the present invention is not limited to these examples. Absent.

[Example 1] (Production of positively charged powder containing an organic semiconductor material)
A compound represented by the following formula (2) as an organic semiconductor material (hereinafter referred to as “compound (2)”) (2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene; melting point (127° C.) and zirconia beads having a diameter of 1-2 mm were put in a container, and the compound (2) was crushed using a bead mill at a rotation speed of 4,500 rpm for 5 minutes. The obtained powder of the compound (2) having a particle size of 10-20 μm was used as a carrier particle having carrier particles P-02 having magnetism as a compound (2): a carrier particle P-02 (a standard carrier for positively charged polar toner sold by The Imaging Society of Japan). Carrier particles were mixed at a mass ratio of 1:10 and stirred to prepare a positively charged powder composed of the compound (2) and carrier particles. It was confirmed from the polarization micrograph shown in FIG. 4 that the obtained powder was composed of the compound (2) and carrier particles.

[Example 2] (Preparation of negatively charged powder containing an organic semiconductor material)
Negative consisting of the compound (2) and carrier particles was carried out in the same manner as in Example 1 except that magnetic carrier particles N-01 (sold by The Imaging Society of Japan: standard carrier for negatively charged polar toner) were used as carrier particles. A powder charged to the above was prepared.

[Example 3] (Spraying and patterning of organic semiconductor material)
A 12 μm thick polyimide film (product name “Pomilan (registered trademark) N”, manufactured by Arakawa Chemical Industry Co., Ltd. as a substrate 1′, a silica hybrid having a structure in which nano silica particles having an average particle diameter of 5 nm are dispersed in a polyimide matrix. "Parylene (registered trademark) C" (manufactured by Nippon Parylene GK) as a gate insulating layer 3'on a polyimide film) with a thickness of 900 nm, and a channel length of 20 μm and a channel width of 5 mm are formed on the upper part of the parylene film. forming a gold electrode as a source electrode 5 and drain electrode 6, to obtain a source-drain board.

Installing the drain board on the stage 25 of the powder patterning device 20 of FIG. 1 as the substrate 21, patterning the organic semiconductor material in the vicinity of the source electrode 5. That is, after the positively charged powder composed of the compound (2) obtained in Example 1 and carrier particles was adhered to the holder 22 composed of a neodymium magnet covered with an insulating film connected to an external power source, the source the horizontal direction (X-axis, Y-axis direction) of the source and drain board as powder comes on the source electrode 5 drain board to adjust the position of the. Then raised the stage 25 to adjust the distance between the source and drain board and the holder 22 to 0.5 mm, the organic semiconductor material by applying a DC voltage of 1.5kV by the external power supply to the holder 22 It was sprayed from the holder 22 to the source and drain board on. The polarizing microscopic photograph of the source electrode 5 peripheral edge definitive source and drain board before the powder spraying illustrated in FIG. 5, FIG polarization microscopic photograph of the source electrode 5 peripheral edge definitive source and drain board after the powder spraying 6 shows. As shown in FIG. 6, it was confirmed that the powder containing the compound (2) was transferred to the vicinity of the source electrode 5.

[Example 4]
The external power source connected to the source electrode 5 on the source and drain board, except using a powder charged negatively consisting of the compounds prepared in Example 2 (2) and the carrier particles in the same manner as in Example 3 They were dispersed organic semiconductor material from the holder to the source and drain board on Te. It was confirmed that the powder of the compound (2) was transferred to the vicinity of the source electrode 5 as in Example 3.

[Example 5]
The voltage applied to the holder 22 by the external power supply, the pulse amplitude 150 V, except for changing the rectangular wave AC voltage having a frequency 10Hz in the same manner as in Example 3, was sprayed with an organic semiconductor material to the source and drain board on. The polarizing microscopic photograph of the source electrode 5 peripheral edge definitive source and drain board before the powder spraying illustrated in FIG. 7, FIG polarization microscopic photograph of the source electrode 5 peripheral edge definitive source and drain board after the powder spraying 8 shows. As shown in FIG. 8, it was confirmed that the powder containing the compound (2) was transferred to the vicinity of the source electrode 5.

[Example 6]
In this example, an example of the organic thin film transistor 10B shown in FIG. 11B was manufactured. A gold electrode is formed as a gate electrode 2 on a polyimide film (product name “Pomilan (registered trademark) N”) having a thickness of 12 μm as a base material 1, and “parylene (as a gate insulating layer 3 is formed as a gate insulating layer 3 on the gold electrode. registered trademark) C "(it was deposited in Japan parylene Limited Liability company, Ltd.) 900nm of thickness to obtain a gate based on plate.

Then overlapped gate board the patterned source and drain board on in Example 3. The thus compounds between the source-drain group Ita及 beauty gate board obtained (2) those which sandwiches (referred to as object to be processed), in FIG. 2 having a heat roll 31, 32 heat laminator Using a commercially available laminator (FUJIPLA's Lamipacker Meister 6 LPD3226), which is an example of No. 30, the temperature of the heat rolls 31 and 32 is 140° C., the nip pressure of the heat rolls 31 and 32 is 5.9 N/cm ² , and the speed is The object to be treated was laminated under the condition of 0.4 m/min to obtain an organic semiconductor thin film composed of the compound (2).

Figure 9 shows the results of confirming the state of the organic semiconductor material in the sample before lamination (organic semiconductor material between the source and drain group Ita及 beauty gate board which is sandwiched) a polarizing microscope. Figure 10 is the result of confirming the state of the organic semiconductor material in the sample taken after passing through a heat roll (source-drain group Ita及 beauty that organic semiconductor thin film between the gate board are formed) by a polarization microscope It is shown. As shown in FIG. 10, the semiconductor layer 4 made of an organic semiconductor thin film was formed between the source electrode 5 and the drain electrode 6 (two vertical lines in the center), and it was found that the organic thin film transistor 10B could be manufactured. It was

Next, the semiconductor characteristics of the organic thin film transistor 10B obtained in Example 6 were measured. The application of the gate voltage and the gate current of the organic thin film transistor 10B are performed using a Keithley Instruments Inc. type 2635A system source meter, and the application of the source/drain voltage and the drain current of the organic thin film transistor 10B are performed by the Keithley. -It carried out using the 6430 type sub femto ampere remote source meter made by Instruments. The current-voltage characteristics of the organic thin film transistor 10B were measured under the condition that the drain voltage of the organic thin film transistor 10B was set to -10V and the gate voltage Vg of the organic thin film transistor 10B was changed to 5 to -10V. The mobility and threshold voltage of the organic thin film transistor 10B were calculated from the obtained current-voltage characteristics of the organic thin film transistor 10B. The calculated mobility was 0.025 cm ² /Vs, the calculated threshold voltage was 0.9 V, and the organic thin film transistor 10B in which the semiconductor layer 4 had a p-type semiconductor characteristic was obtained.

From the results described in each example, not only can the organic semiconductor device be manufactured by a solventless process consistently from the patterning of the organic semiconductor to the thinning process, but the organic semiconductor device manufactured by this method has high semiconductor characteristics. Was shown to have. According to the method for manufacturing an organic semiconductor device of each example, when forming an organic semiconductor thin film, not only a vacuum process and a volatile organic solvent are not required, but also an organic semiconductor thin film can be formed in an extremely short time. It was confirmed. Therefore, it was confirmed that the method for manufacturing the organic semiconductor device of each example was a high-throughput manufacturing method.

1, 1'base material 2 gate electrode 3, 3'gate insulating layer (insulating layer)
4 Semiconductor layer (organic semiconductor thin film)
5 source electrode 6 drain electrodes
1 0A organic thin film transistor (organic semiconductor device)
10B Organic Thin-Film Transistor 20 Powder Patterning Device 21 Base Material 22 Holder 23 Electrode 24 Wiring 25 Stage 30 Thermal Laminator 31, 32 Thermal Roll 33 Feed Roll 34 Workpiece 40 Ultrasonic Welding Machine 41 Ultrasonic Oscillator 42 Ultrasonic Transducer 43 Booster 44 Horn 45 Pressing Mechanism 45a Arm 45b Support 46 Heating Stage 46a Heater

Claims (14)

A method of manufacturing an organic semiconductor device by patterning an organic semiconductor material, comprising:
A method for manufacturing an organic semiconductor device, comprising the step of patterning a charged powder containing an organic semiconductor material and carrier particles on a substrate by applying an electrostatic field. The method for manufacturing an organic semiconductor device according to claim 1, wherein the organic semiconductor material contains a charged organic semiconductor material. The method for manufacturing an organic semiconductor device according to claim 1, further comprising a step of thinning the organic semiconductor material by heat and pressure after the step of patterning. The method of manufacturing an organic semiconductor device according to claim 3, wherein the step of thinning the film includes a step of thinning the organic semiconductor material by applying heat and pressure to the organic semiconductor material with a heat laminator including a heat roll. 4. The method of manufacturing an organic semiconductor device according to claim 3, wherein the step of thinning includes a step of thinning the organic semiconductor material by applying ultrasonic vibration while applying pressure to the organic semiconductor material. The organic material according to claim 1 or 2, wherein the patterning step is a step of magnetically separating carrier particles from a charged powder containing an organic semiconductor material and carrier particles, and spraying only the organic semiconductor material onto a base material. Manufacturing method of semiconductor device. In the thinning step, another base material is placed on the patterned organic semiconductor material on one base material, and the organic semiconductor material is sandwiched between a pair of base materials. The method for manufacturing an organic semiconductor device according to claim 3, which is a step of thinning the organic semiconductor material by simultaneously applying heat and pressure from the upper portion of the placed substrate. The method for manufacturing an organic semiconductor device according to claim 7, wherein the pair of base materials are resin films. The method for manufacturing an organic semiconductor device according to claim 1, wherein the organic semiconductor device is an organic thin film transistor. The organic thin film transistor, a source electrode and a drain electrode arranged to be separated from each other, a semiconductor layer including an organic semiconductor thin film made of an organic semiconductor material arranged between the source electrode and the drain electrode, A gate electrode disposed so as to face the semiconductor layer, and an organic field effect transistor comprising an insulating layer disposed between the semiconductor layer and the gate electrode on a substrate,
The patterning step is a step of patterning a powder containing a charged organic semiconductor material and carrier particles by applying an electrostatic field to the source electrode, the gate electrode, or a position in the vicinity thereof,
The manufacturing method further includes, after the patterning step, sandwiching the organic semiconductor material between a pair of base materials, and applying heat and pressure to the organic semiconductor material simultaneously from above the base materials. The method for manufacturing an organic semiconductor device according to claim 9. Charged powder,
A powder containing an organic semiconductor material and carrier particles. The powder according to claim 11, wherein the organic semiconductor material includes a charged organic semiconductor material. The powder according to claim 11 or 12, wherein the organic semiconductor material is a crystalline low molecular weight organic semiconductor compound. The crystalline low molecular weight organic semiconductor compound is represented by the following general formula (1)
(In the formula, R ₁ and R ₂ each independently represent a hydrogen atom, an alkyl group, an alkenyl group which may have a substituent, an alkynyl group which may have a substituent, or a substituent which may have a substituent. Represents an aryl group, an optionally substituted heterocyclic group, an alkoxyl group or an alkoxyalkyl group, R ₁ and R ₂ may be the same or different, and m and n are each independently 0. Or represents 1)
The powder according to claim 13, which is a thienothiophene derivative represented by: